Really fun game, cute art and the sounds just fit everything in it.
The only thing I would have change is the crystal, they are a great idea and make the game don't feel too repetitive, but at a first look it seens like a collectable, even after reading the how to play, but after dying once for this we don't forget haha, but I would make this like the color of the pipes are different. But I think this is only a art choice.
Overall, really fun game that triggers the player into beating its best score, congrats!!!